Copy install fix from #1001

Author: jagerman

CMakeLists.txt

@@ -108,8 +108,7 @@ if(NOT (CMAKE_VERSION VERSION_LESS 3.0))  # CMake >= 3.0
 endif()
 
 if (PYBIND11_INSTALL)
-  install(FILES ${PYBIND11_HEADERS}
-          DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/pybind11)
+  install(DIRECTORY ${PYBIND11_INCLUDE_DIR}/pybind11 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR})
   # GNUInstallDirs "DATADIR" wrong here; CMake search path wants "share".
   set(PYBIND11_CMAKECONFIG_INSTALL_DIR "share/cmake/${PROJECT_NAME}" CACHE STRING "install path for pybind11Config.cmake")